Place beef in a large bowl or larger heavy-duty resealable plastic bag. Pour marinade over beef, toss to combine and cover tightly with plastic wrap or carefully seal bag. Refrigerate 1 to 3 hours (can be prepared up to 24 hours ahead),

Heat grill. Remove beef from refrigerator and stir mushrooms into marinade. Thread onto skewers, alternating beef, mushrooms and tomatoes, if using. Grill 8 to 10 minutesm turning skewers occasionally. Remove from grill while meat is still pink in the center. (It will continue to cook a little after it comes off the heat.) Transfer to a sering platter.